Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-03-18' into staging

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-03-18' into staging

QAPI patches for 2016-03-18

# gpg: Signature made Fri 18 Mar 2016 09:54:57 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2016-03-18:
  qapi: Use anonymous bases in QMP flat unions
  qapi: Allow anonymous base for flat union
  qapi: Make BlockdevOptions doc example closer to reality
  qapi: Don't special-case simple union wrappers
  qapi: Drop unused c_null()
  qapi: Inline gen_visit_members() into lone caller
  qapi-commands: Inline single-use helpers of gen_marshal()
  qapi-commands: Utilize implicit struct visits
  qapi-event: Utilize implicit struct visits
  qapi-event: Drop qmp_output_get_qobject() null check
  qapi: Emit implicit structs in generated C
  qapi: Adjust names of implicit types
  qapi: Make c_type() more OO-like
  qapi: Fix command with named empty argument type
  qapi: Assert in places where variants are not handled

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>